1. Field of Invention
The present invention relates to a projector technology, more specifically, to a projector and a method for acquiring a coordinate of a bright spot.
2. Description of Related Art
In performing projection by a projector, a high brightness point light source, such as a laser point light source and an LED spot, is usually needed to project a bright spot onto a projection area of the projector, so as to facilitate a demonstrator's demonstrating. Meanwhile, to further facilitate the demonstrating, it is desired that the projector not only can independently complete many works that otherwise would be accomplished depending on a computer previously, such as marking on a projected document; but also can communicate with a computer operating to perform the projection, such that the projector may automatically accomplish many complicated functions that otherwise would be accomplished on the computer by the demonstrator, such as page turning, mouse moving, button clicking and the like. Therefore, it is necessary for the projector to acquire the coordinate of the laser spot projected by the demonstrator, so as to achieve the functions such as marking, page turning, mouse moving, button clicking and the like as described above.
Currently, there are two solutions for acquiring the coordinate of the bright spot (the coordinate of the laser spot) by utilizing the projector.
FIG. 1 is a schematic diagram showing a structure of a system for acquiring the coordinate of the laser spot according to the first solution in the prior art.
As shown in FIG. 1, the system for acquiring the coordinate of the laser spot comprises a projector 1, a camera 2, and a computer 3. The computer 3 comprises a video capture card 31 and a video display card 32. The video capture card 31 is connected to the camera 2, the video display card 32 is connected to the projector 1, and the camera 2 is placed directly above the projector 1.
When the demonstrator uses the projector 1 to perform projection, and also uses a laser point light source to project the laser spot onto the projection area, the camera 2 first takes an image of the laser spot, and then sends the taken laser spot image to the video capture card 31.
The video capture card 31 performs capture on the received laser spot image, to thereby obtain the captured laser spot image information.
The computer 3 processes the captured laser spot image information by using a laser spot real-time detecting program running in the computer 3, according to the laser spot image received by the video capture card 31, and then obtains the coordinate of the laser spot for operating the projector 1 connected thereto.
The main disadvantages for this solution lie in that, it is the computer system that acquires the laser spot information, and the projector itself can not acquire the position of the laser spot; and if the projector 1 is moved away from the selected computer system, it does not have the function for acquiring the position of the laser spot.
FIG. 2 is a schematic diagram showing a structure of a system for acquiring the coordinate of the laser spot according to the second solution in the prior art.
As shown in FIG. 2, the system for acquiring the coordinate of the laser spot comprises a projector 1, a camera 2, a computer 3, a charge-coupled device (CCD) 4, and a processing system 5, wherein, the computer 3 comprises a video display card 32 connected to the camera 1, for performing projection operation.
In the second solution, the camera 2 is placed beside the camera 1, and a laser spot image taken by the camera 2, after being imaged in the CCD 4, is input into the processing system 5.
Since the processing system 5 operates independently of the computer 3, it can not directly obtain the imaging size and position on the CCD 4 for the image projected by the projector 1. The processing system 5 has to use an image edge extraction algorithm to determine the imaging size and position, and finally obtains the coordinate of the laser spot after complicated computations.
The main disadvantages for this solution lie in that, since the imaging size and position on the CCD or other imaging devices, such as a CMOS (COMPLEMENTARY METAL OXIDE SEMICONDUCTOR) device and a JFET (JUNCTION FIELD-EFFECT TRANSISTOR) device, for the image projected by the projector are unknown, it is necessary to first use the image edge extraction algorithm to determine the imaging size and position, and then obtain the coordinate of the laser spot after complicated computations, thus resulting in a low speed and a low accuracy.
Therefore, in view of the disadvantages of the solutions as described above, it is necessary to design a projector for acquiring the coordinate of the laser spot, which can be used independently and expediently without relying on the computer system, and can acquire the coordinate of the laser spot in a simple, fast and accurate manner.